The present invention relates to a connector that produces a large contact force between contacts thereof and contacts of a connection counterpart with a small operation force. Such a connector may generally be called a low insertion force connector or a zero insertion force connector which are collectively called a ZIF connector throughout the specification and the claims.
FIG. 12 shows a conventional ZIF connector, which corresponds to one described in JP-A-H05-343146. In FIG. 12, a housing 51 is formed with a plurality of holes 52 arranged in line at regular intervals. A contact 53 is received in each hole 52. Each contact 53 has a first contact member 53A and an elastically deformable second contact member 53B, which cooperatively form substantially a U-shape. Each of lead pins of a connection counterpart (not shown) is inserted between the corresponding first and second contact members 53A and 53B in a direction identified by an arrow. An actuator 54 and a cam 55 are further received in the housing 51. The actuator 54 has a plurality of projecting portions 54A corresponding to the contacts 53, respectively.
When the cam 55 is rotated in a direction of an arrow, the actuator 54 moves in a left direction in the figure. Then, each projecting portion 54A of the actuator 54 pushes the second contact member 53B of the corresponding contact 53. This causes each second contact member 53B to be elastically deformed so that each lead pin is sandwiched under pressure between the corresponding first and second contact members 53A and 53B. In this manner, the lead pins are connected to the contacts 53, respectively.
In the foregoing conventional ZIF connector, however, when the thickness of the lead pin is small, inasmuch as the displacement of the second contact member 53B is small, a sufficient contact force can not be produced between the lead pin and the first and second contact members 53A and 53B. Particularly, when the connector has a multi-contact structure with a small operation force, a sufficient displacement of the second contact member 53B can not be achieved to result in a small contact force, so that a reliable contact can not be ensured between the lead pin and the first and second contact members 53A and 53B.
Further, inasmuch as there is provided no lock mechanism for locking the movement of the cam 55, when a load such as vibration or impact is applied to the ZIF connector from the exterior after the connection counterpart is connected thereto, it may be possible that the cam 55 rotates in a reverse direction to release the fitted state between the contacts 53 and the lead pins so that the lead pins are disengaged from the contacts 53.
There have been proposed other ZIF connectors as described in, for example, JP-A-H08-203622 and JP-A-200243006, wherein, however, the foregoing problems are still outstanding.